Uncovering a Gene Defect’s Role in Autism-Type Behaviors

A defective pten gene can lead to disruptions in the activity of neuronal mitochondria and autism-type behaviors in mice, according to a new study from NIEHS grantees. Pten is defective in some children with autism, and this new insight into how the gene affects the brain could lead to new drug targets.

To investigate the effects of a defective pten gene, the researchers studied mice with neurons containing only one copy of the gene, rather than the normal two. By four to six weeks after birth, the neurons of these mice showed malfunctioning mitochondria. At 20 to 29 weeks, the researchers observed a dramatic increase in DNA damage and mitochondrial dysfunction. The mice also began to avoid their littermates and engage in repetitive grooming, behaviors associated with autism. Mice with two copies of the pten gene did not have malfunctioning mitochondria or behavioral problems.

The researchers also found that defective pten interacted with the p53 gene to impair mitochondrial function in mice. This led to an increase in mitochondrial DNA damage and abnormal levels of energy production in the cerebellum and hippocampus, brain regions that are critical for social behavior and cognition.